Dan Doel | 1 Mar 04:26 2008

Announce: category-extras 0.1

Hello everyone,

While fooling about with generalized tries a night or two ago, I found myself 
once again interacting with fixed points of shape functors and the like, and 
so decided it was time to finish cabalizing David Menendez' excellent 
category theory inspired modules.[1]

So, it is my pleasure to announce version 0.1 of category-extras. This is an 
initial import of the code, with only what work it took to get things 
compiling properly. As such, some of the documentation is a bit scanty, and 
there is some overlap with other packages (notably, TypeCompose, off the top 
of my head), but I hope to rectify that later.

Notable bits include:

 * Control.Comonad
   * Control.Comonad.Context -- the state-in-context monad
 * Control.Functor.Adjunction
   -- a class for adjoint functors, and their associated (co)monads
 * Control.Recursion
   -- Various generalized recursion operators (cata/zygo/histo/apomorphisms)
   -- A class for associating fixpoint data types to their shape functors

Also included are some Data.* modules with some comonadic data types (infinite 
trees and streams, for instance), but they are in the 
as-yet-poorly-documented section of the package.

Haddock 2.0 is required to build what documentation there is for 
Control.Functor.Transform, as it uses type operators. However, the rest 
should be compatible with earlier versions of haddock. Some modules are 
(Continue reading)

ICFP08 Final CFP

                        Final Call for Papers
    ICFP 2008: International Conference on Functional Programming
              Victoria, BC, Canada, 22-24 September 2008
                  Submission deadline: 2 April 2008

ICFP 2008 seeks original papers on the art and science of functional
programming. Submissions are invited on all topics from principles to
practice, from foundations to features, from abstraction to
application.  The scope includes all languages that encourage
functional programming, including both purely applicative and
imperative languages, as well as languages with objects and
concurrency. Particular topics of interest include
  * Applications and Domain-Specific Languages
  * Foundations
  * Design
  * Implementation
  * Transformation and Analysis
  * Software-development Techniques
  * Functional Pearls
  * Practice and Experience

Important Dates (at 09:00 Apia time, UTC-11)
Submission:       2 April 2008
Author response:  21 May 2008
Notification:     16 June 2008
Final papers due:  7 July 2008

Call for Papers (full text)
(Continue reading)

Janis Voigtlaender | 4 Mar 12:27 2008

Announce: online free theorems generator now with PDF output

The free theorems generator online at:

   http://linux.tcs.inf.tu-dresden.de/~voigt/ft ,

previously announced here:

   http://www.haskell.org/pipermail/haskell/2007-October/019917.html ,

now allows to export generated theorems and associated information as
.pdf files with nice mathematical markup.

The new feature was implemented by Florian Stenger. It builds on Patryk
Zadarnowski's lambdaTeX package.

Have fun,


Dr. Janis Voigtlaender
mailto:voigt <at> tcs.inf.tu-dresden.de
Alistair Bayley | 5 Mar 10:24 2008

ANN: Takusen 0.8

Oleg and I are pleased to announce the release of Takusen 0.8.

(Don Stewart did an interim 0.7 release for us a few weeks ago,
and added us to Hackage. This release is a tidy-up of some loose
ends, and some bug fixes. Hence, I've summarise the changes
since the 0.6 release.)

Changes since 0.6:

 - ODBC support. This still has a few gaps (and probably bugs and rough edges)
   but should be fairly usable.

 - support for reusable/persistent sessions, so you can hang onto
   the connection object between invocations of withSession
   (this was in release 0.6 but omitted from the release notes).

 - improvements to the Cabal Setup scripts, which should give
   better experiences for ghc-6.4, ghc-6.6, and ghc-6.8.
   The (eventual) 1.4 release of Cabal should be able to build our
haddock docs, too.

 - improved UTF8 decoder (marshals directly from buffer).

The release bundle:
The latest code:
  darcs get http://darcs.haskell.org/takusen

(Continue reading)

Derek Elkins | 6 Mar 07:58 2008

ANN: Parsec 3.0.0

This is a first release of the Parsec 3, the Google Summer of Code of
Paolo Martini.

The main changes are:
    * The Parser monad has been generalized into a ParserT monad        

    * The parsers have been generalized to work over a stream of any 
      type, in particular, with byte strings.

    * There is Haddock documentation for almost all functions in the 
      Text.Parsec tree.

    * The Parser monad now has Applicative/Alternative instances

    * A "compatibility" Text.ParserCombinators.Parsec tree for the old 
      Parsec.  It's not perfect, but it should work with most Parsec 2

This package should be installable from with cabal install or with the
standard cabal invocations.

Cabal release:

The darcs repository is at:

Note that this package is a new version of the parsec package and so
will hide the old parsec- package.
(Continue reading)

Malcolm Wallace | 6 Mar 15:11 2008

Google summer of code

Reply-To: haskell-cafe <at> haskell.org

			Google Summer of Code

As many of you will already know, Google is running its "Summer of Code"
project again this year, and haskell.org is once again going to apply to
be a mentoring organisation.  Are you a student who would like to earn
money for hacking in Haskell?  Or are you a non-student who has a cool
idea for a coding project but no time to do it yourself?

Well, our wiki to gather ideas is now up-and-running again:

Add yourself to the list of interested people!  Especially potential

There are some ideas still there from last year, in the trac tickets.
However, due to the amount of spam accumulating there, I suggest that
this year, we use the haskell-cafe email list as a place to put out
project ideas, solicit feedback on them, and look for interested people.
Prefix any message subject line with with [GSoC] to help others find

Google will start accepting student applications on 24th March, but now
is the time to start gathering thoughts and matching up interesting
ideas with interested people.

The official timeline is as follows:

 March 12: Mentoring organization application deadline
(Continue reading)

Johannes Waldmann | 7 Mar 07:51 2008

Local Haskell meeting + Hackathon, Leipzig, Germany, April 18-20

HaL 3, the third Haskell in Leipzig meeting,
will take place on Friday, April 18, 2008 (late afternoon).

Tentative program:

- Janis Voigtlaender: Theorems for free
- J├╝rgen Nicklisch-Franken: The Making of Leksah

The HaL meeting will be combined with a Hackathon weekend (19.-20.4.),
where we want to work on the Haskell Eclipse plugin
(refactoring, IDE integration, ...),
see http://leiffrenzel.de/eclipse/wiki/doku.php

For more details and registration, see http://iba-cg.de/hal3.html.

Note: For HaL, we could use one more talk (30 min, in German or English)
so if you have something, please tell us.  Preference will be given
to reports on Haskell in (business) applications.

Alf Richter (iba Consulting) and Johannes Waldmann (HTWK Leipzig)
Samir Genaim | 9 Mar 00:29 2008

PLID'08: 1st Call for Contributions

       *         The Fourth International Workshop             *
       *                         on                            *
       *   Programming Language Interference and Dependence    *
       *                                                       *
       *     co-located with LOPSTR'08, PPDP'08 and SAS'08     *
       *                                                       *
       *           15 July, 2008, Valencia, Spain              *
       *                   		                       *
       *      Venue: The Technical University of Valencia      *
       *                                                       *
       *              1st Call for Contributions               *
       *                                                       *
       *   http://www.clip.dia.fi.upm.es/Conferences/PLID08    *
       *                                                       *

Important Dates

Expression of interest 	   	June 1,  2008
Extended abstract 	   	June 15, 2008
Workshop			July 15, 2008

Workshop Description

Interference and  dependence are  closely related concepts,  the first
being the observable phenomenon  connected to the second. Interference
(Continue reading)

Don Stewart | 9 Mar 22:33 2008

Haskell Weekly News: March 09, 2008

Haskell Weekly News
Issue 71 - March 09, 2008

   Welcome to issue 71 of HWN, a newsletter covering developments in the
   [1]Haskell community.

   Another busy week on the Haskell library front, with around 100 new
   and updated libraries and tools on Hackage.

   1. http://haskell.org/


   Google Summer of Code. Malcolm Wallace [2]announced Google is running
   its 'Summer of Code' project again this year, and Haskell.org is once
   again going to apply to be a mentoring organisation. If you're
   interested in earning money to hack on Haskell, and helping out the
   community, [3]take a look at the wiki.

   2. http://article.gmane.org/gmane.comp.lang.haskell.cafe/37273
   3. http://hackage.haskell.org/trac/summer-of-code

   Haskell in the browser. Dimitry Golubovsky [4]announced that the YHC
   JavaScript backend is now in alpha testing, and is open to
   experimentation for those wanting to write Haskell directly for the

(Continue reading)

Elvira Albert | 10 Mar 10:14 2008

PPDP 2008 - 2nd Call for Papers

                  ACM PPDP 2008 -  Call For Papers

            10th ACM-SIGPLAN International Symposium on
        Principles and Practice of Declarative Programming

                Valencia, Spain, July 15-17, 2008



Submission:   April 10, 2008
Notification: May 15, 2008
Conference:   July 15-17, 2008

SCOPE: PPDP 2008  is a forum for researchers  and practitioners in the
declarative programming communities. It solicits papers on all aspects
of logic, constraint and functional programming, as well as on related
paradigms  such   as  visual  programming,   executable  specification
languages,  database   languages,  AI  and   knowledge  representation
languages for the "semantic web".

MAIN TOPICS: Logic,  Constraint, and Functional Programming; Database,
AI  and   Knowledge  Representation  Languages;   Visual  Programming;
Executable  Specification for  Languages; Applications  of Declarative
Programming;  Methodologies   for  Program  Design   and  Development;
Declarative   Aspects  of   Object-Oriented   Programming;  Concurrent
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